php - Custom Walker - split child menu items into columns

one text

I have this pretty basic custom walker for my nav. Is there any way to split the child menu items into columns, for example, if we have 6 child nav items in the first nav item, how can I put 3 in one column and 3 in another column?

I know I can do that with CSS, but I would extend it further to group items based on their count and that won't work with CSS.

class SC_Menu_Walker extends Walker_Nav_Menu {
function start_el(&$output, $item, $depth=0, $args=[], $id=0) {

    global $wp_query;

    $indent = ( $depth ) ? str_repeat( "\t", $depth ) : '';

    $this->curItem = $item;

    $class_names = $value = '';

    $classes = empty( $item->classes ) ? array() : (array) $item->classes;          
    $class_names = join( ' ', apply_filters( 'nav_menu_css_class', array_filter( $classes ), $item, $args, $depth ) );

    $class_names = ' class="'. esc_attr( $class_names ) . '"';

    $output .= $indent . '<li id="menu-item-'. $item->ID . '"' . $value . $class_names .'>';

    if ($item->url && $item->url != '#') {
        $output .= '<a href="' . $item->url . '">';
    } else {
        $output .= '<span>';
    }

    $output .= $item->title;
}

function start_lvl(&$output, $depth = 0, $args = array()) {

    $sc_page_item_label = get_post_meta( $this->curItem->object_id, '_sc_page_item_label', true );
    $sc_page_item_description = get_post_meta( $this->curItem->object_id, '_sc_page_item_description', true );
    $sc_page_item_url = get_post_meta( $this->curItem->object_id, '_sc_page_item_url', true );
    $sc_page_item_page_url = get_page_link($sc_page_item_url);

    $secondMenuClass="sub-menu__list o-sm-col-12 o-lg-col-7 u-font-size-medium";
    $wrapperScrollStart="";

    if ($depth == 1) {
        $secondMenuClass="sub-menu__list sub-menu__list--scrollbar";
        $wrapperScrollStart="<div class='sub-menu__inner'>";
        $wrapperScrollEnd ='</div>';
    }
    
    $output .= '<div class="sub-menu sub">
    <div class="o-custom-container">
    <div class="sub-menu__wrapper_info o-sm-col-12 o-lg-col-5"><div class="o-lg-col-7"><h5>'.$sc_page_item_label.'</h5> <div class="u-font-size-medium">'.$sc_page_item_description.'</div></div>
    <div>
    <div class="c-learn-more-holder">
        <div class="c-learn-more">
            <a href="'.$sc_page_item_page_url.'" class="c-learn-more-link "></a>
            <div class="c-learn-more-title">Learn more</div>
        </div>
    </div>
    </div>
    </div>'.$wrapperScrollStart.'<ul class="'.$secondMenuClass.'">';
}

//end of the sub menu wrap
function end_lvl(&$output, $depth = 0, $args = array()) {

    $wrapperScrollEnd = '';

    if ($depth == 1) {
        $wrapperScrollEnd ='</div>';
    }

    $wrapperScrollEnd ='</div>';
    $output .= '</ul>'.$wrapperScrollEnd.'</div>';
}

}